(a) Field of the Invention
The present invention relates to a vacuum container for a heat-vacuum test chamber or the like.
(b) Description of the Prior Art
A heat-vacuum test chamber as used in this specification is a device for simulating the thermal and vacuum environment encountered by satellites, satellite equipment and so on in space orbits. A test sample is placed in a vacuum container of this device to confirm its ability to resist various environmental factors. Such a heat-vacuum test chamber is used for testing not only equipment related to space but also aeronautical and ground equipment.
Since the vacuum container of a conventional heat-vacuum test chamber is made of metal, electromagnetic waves radiated by a sample placed in the vacuum container do not penetrate the walls of the vacuum container. For this reason, the interference between electromagnetically interfering equipment such as an electron tube which operates only in a vacuum and other equipment cannot be checked. Furthermore, when a sample to be tested with plasma or the like has a high voltage circuit, phenomena occur such as electrical discharge inside the vacuum container, at the lead-in terminal and so on, and the testing becomes difficult to perform.
Therefore, a conventional heat-vacuum test chamber or a vacuum testing device has been limited with respect to its impermeability to electromagnetic waves and to its safety requirements related to high voltage power sources due to the fact that the material of the vacuum container is a metal such as SUS.